EVOLUTION Chapter 10 Page 26 Charles Darwin Darwins

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EVOLUTION Chapter 10 Page 26

EVOLUTION Chapter 10 Page 26

Charles Darwin

Charles Darwin

Darwin’s Theory of Evolution n Evolution, or change over time, is the process by

Darwin’s Theory of Evolution n Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms.

How do you think Darwin came up with his theory?

How do you think Darwin came up with his theory?

Voyage of the Beagle

Voyage of the Beagle

Voyage of Beagle YEAR: 1831 n Captain: Charles Darwin n Ship: H. M. S.

Voyage of Beagle YEAR: 1831 n Captain: Charles Darwin n Ship: H. M. S. Beagle n Destination: Galapagos Islands near the continent of. n Findings: evidence for showing how life changes over time. n

Fossils

Fossils

Living Organisms and Fossils n As Darwin studied fossils, new questions arose. u Why

Living Organisms and Fossils n As Darwin studied fossils, new questions arose. u Why had so many of these species disappeared? u How were they related to living species?

The Galapagos Island n Darwin was fascinated in particular by the land tortoises and

The Galapagos Island n Darwin was fascinated in particular by the land tortoises and marine iguanas in the Galápagos. n The shape of a tortoise's shell could be used to identify which island a particular tortoise inhabited.

Animals

Animals

The Journey Home n Hypothesis: Separate species may have arose from an original ancestor

The Journey Home n Hypothesis: Separate species may have arose from an original ancestor

Lamarck’s Theory of Evolution n (Giraffe necks) Inheritance of Acquired Traits Are you still

Lamarck’s Theory of Evolution n (Giraffe necks) Inheritance of Acquired Traits Are you still paying Attention?

Struggle For Existence & Survival of The Fittest

Struggle For Existence & Survival of The Fittest

Natural Selection n Over time, natural selection results in changes in inherited characteristics of

Natural Selection n Over time, natural selection results in changes in inherited characteristics of a population. These changes increase a species fitness in its environment

Evolution by Natural Selection n The Struggle to Survive-members of each species have to

Evolution by Natural Selection n The Struggle to Survive-members of each species have to compete for food, shelter, other life necessities

Steps of Natural Selection The Struggle to Survive - members of each species have

Steps of Natural Selection The Struggle to Survive - members of each species have to compete for food, shelter, or other life necessities n Over Production - Some will survive others will not n Inherited Variation - every species has its own set of traits n Successful Reproduction - Best adapted to its environment they are more likely to have offspring that will survive. n

Evidence of Evolution n n The Fossil Record Geographic Distribution of Living Things-similar environments

Evidence of Evolution n n The Fossil Record Geographic Distribution of Living Things-similar environments have similar types of organisms Homologous Body Structures Similarities in Early Development

Evidence for Evolution n Vestigial organs-organs that serve no useful function in an organism

Evidence for Evolution n Vestigial organs-organs that serve no useful function in an organism n i. e. ) appendix, miniature legs, arms

Summary of Darwin’s Theory n Individuals in nature differ from one another n Organisms

Summary of Darwin’s Theory n Individuals in nature differ from one another n Organisms in nature produce more offspring than can survive, and many of those who do not survive do not reproduce.

Summary of Darwin’s Theory n Because more organisms produce than can survive, each species

Summary of Darwin’s Theory n Because more organisms produce than can survive, each species must struggle for resources n Each organism is unique, each has advantages and disadvantages in the struggle for existence

Summary (cont. ) n Individuals best suited for the environment survive and reproduce most

Summary (cont. ) n Individuals best suited for the environment survive and reproduce most successfully n Species change over time